Gas blast circuit breaker



Feb- 25, 1947. G. BRUHLMANN GAS BLAST CIRCUI'.1 BREAKER Filed Feb. 17, 1944 A Zr/7/7/717l//7/71 7/7/7/7/7/7/7/ 7 Patented Feb. 25, 1947 GAS BLAST CIRCUIT BREAKER Gottfried Brhlmann, Baden,

signor to Aktiengesellschaft Brown,

Switzerland, as-

Boveri &

Cie., Baden, Switzerland Application February 17, 1944, Serial N0. 522,772 In Switzerland January 18, 1943 (Cl. G-148) 3 Claims.

The invention concerns a circuit breaker where the arc is extinguished by a flow of extinguishing medium, for instance pressure gas, the circuit breaker having at least one hollow contact through which the extinguishing medium discharges. Such circuit breakers have been provided with a resistance, which by means of a spark gap is connected in parallel with the circuit breaker contacts and serves to assist the interruption of the arc and to prevent a rapid rise of the recovery voltage. For the smooth opera tion of such circuit breakers it is oi fundamental importance that the spark gap should be located at the discharge side of the pressure gas and constructed in such a manner that the spark gap is certain to ignite and extinguish for all switching conditions.

In a gas-blast circuit breaker with at least one hollow contact through which pressure gas flows and a resistance which is switched by a spark gap, the aforementioned object is achieved in accordance with the invention by constructing the spark gap so as to consist of an electrode connected with the resistance and which in the direction of the gas blast is the outermost electrode, and at least one rod-shaped counter-electrode, which forms a, prolongation of the hollow contact and is metallically connected with the latter and ends outside the ow axis in the ionized space.

Constructional examples of the invention are illustrated diagrammatically in Figs. 1-3 of the accompanying drawing, all elements which are not essential for an understanding of the invention having been omitted.

In the gures a denotes the stationary hollow contact through which the gas flows and which co-operates with the moveable pin contact b..

This moveable contact b closes the gas discharge opening in the hollow contact a when the contacts are in the closed position. The resistance d is connected with the electrode ci and by means of a sliding contact with the moveable circuit breaker pin contact b. Resistance d is switched by a spark gap consisting of the electrode c1, which in the direction of the gas blast is the outermost electrode, and at least one extension piece cz acting as a counter-electrode, which is metallically connected to the hollow contact a and ends outside the flow axis in the ionized discharge space e.

The shape of the counter-electrodes c2 is quite optional and they can either be directly connected with the hollow contact, as shown in Figs. 1 and 2, or by means of an intermediate piece f as indicated in Fig. 3. lThe number of counter- Si electrodes employed is also optional; two rods located diametrically opposite to each other at the opening of the hollow contact can for instance be used. The electrodes c1-c2 of the spark gap can be so arranged that their ends overlap in the axial direction, as shown in Fig. 1, or alternatively as shown in Fig. 2, so that they are some distance apart in the axial direction. The free ends of the electrodes of the spark gap in the ionized space can be made either with a sharp edge or rounded oii in any desirable manner.

I claim:

l. A gas blast circuit breaker comprising a flat ring-like contact through which the. gas blast ilows, a movable contact adapted to move away from said ring-like contact in a direction opposed to the ilow of said gas blast, an electrode spaced apart from said ring-like contact opposite from said movable contact, a resistance connection interposed between said electrode and said movable contact and a rod shaped counter electrode formed as an extension of said ring-like contact and metallically connected therewith, said counter electrode extending in the direction of ilow of said gas blast and ending outside of the ilow axis in the ionized space.

2. A gas blast circuit breaker as claimed in claim 1 in which a pair of rod like counter electrodes are formed as extensions of said ring-like contact and are positioned diametrically opposite to each other at the opening of the hollow contact.

3. A gas blast circuit breaker as claimed in claim 1 in which the ends oi the electrodes of the spark gap overlap in an axial direction.

GOTTFRIED BRHLMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,287,039 Jansson June 23, 1942 2,290,004 Thommen July 14, 1942 1,384,469 Jones July 12, 1921 1,898,901 Ruppel Feb. 21, 1933 1,961,475 Clerc June 5, 1934 1,982,134 Clerc Nov. 27, 1934 2,306,242 Bartlett Dec. 22, 1942 2,345,724 Baker et al Apr. 4, 1944 2,349,095 Henley May 16, 1944 2,353,729 Jensen July 18, 1944 2,365,134 Amer et al Dec. 12, 1944 

